Cross-sectional anthropometric study of the external ear.

This cross-sectional anthropometric study was aimed at estimating expansion of the external ear during adult life, in order to evaluate the extent to which anatomical features appearing in earprints may vary with time. A review of the literature was provided. Data extracted from photographed ears of 1353 subjects were analyzed. The effect of age on auricle length, earlobe length, and auricle width was explored using univariate analyses of variance. The regression coefficients of age on these dimensions were, respectively, 0.178, 0.115, and 0.073 mm/yr for males, and 0.162, 0.100, and 0.073 mm/year for females (p=0.000). Regression coefficients of age corrected for stature were assumed to be less accurate. Anthelix prominence and helix width were analyzed using data of 175 subjects, and appeared unaffected by age. As lobe expansion appeared to exceed the estimated cartilage expansion, it was assumed that particularly the imprint of the lobe would be less stable with time.